Book Image

Android Studio 4.0 Development Essentials - Java Edition

By : Neil Smyth
Book Image

Android Studio 4.0 Development Essentials - Java Edition

By: Neil Smyth

Overview of this book

Android rolls out frequent updates to meet the demands of the dynamic mobile market and to enable its developer community to lead advancements in application development. This book focuses on the updated features of Android Studio (the fully integrated development environment launched by Google) to build reliable Android applications using Java. The book starts by outlining the steps necessary to set up an Android development and testing environment. You’ll then learn how to create user interfaces with the help of Android Studio Layout Editor, XML files, and by writing the code in Java. The book introduces you to Android architecture components and advanced topics such as intents, touchscreen handling, gesture recognition, multi-window support integration, and biometric authentication, and lets you explore key features of Android Studio 4.0, including the layout editor, direct reply notifications, and dynamic delivery. You’ll also cover Android Jetpack in detail and create a sample app project using the ViewModel component. Finally, you’ll upload your app to the Google Play Console and handle the build process with Gradle. By the end of this book, you’ll have gained the skills necessary to develop applications using Android Studio 4.0 and Java.
Table of Contents (88 chapters)
88
Index

68.6 Adding the Repository

Add a new class named ProductRepository to the project, with the Class option selected. The repository class will be responsible for interacting with the Room database on behalf of the ViewModel and will need to provide methods that use the DAO to insert, delete and query product records. With the exception of the getAllProducts() DAO method (which returns a LiveData object) these database operations will need to be performed on separate threads from the main thread using the AsyncTask class.

Remaining within the ProductRepository.java file, add the code for the search AsyncTask. Also add a method named asyncFinished() which will be called by the query AsyncTask to return the search results to the repository thread:

package com.ebookfrenzy.roomdemo;

 

import android.os.AsyncTask;

import androidx.lifecycle.MutableLiveData;

import java.util.List;

 

public class ProductRepository {

 

    private...